gno/usr.man/man3/getcwd.3

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.\"     @(#)getcwd.3	8.2 (Berkeley) 12/11/93
.\"
.TH GETCWD 3 "18 December 1996" GNO "Library Routines"
.SH NAME
.BR getcwd ,
.BR getwd
\- get working directory pathname
.SH SYNOPSIS
#include <unistd.h>
.sp 1
char *
\fBgetcwd\fR (char *\fIbuf\fR, size_t \fIsize\fR);
.br
char *
\fBgetwd\fR (char *\fIbuf\fR);
.SH DESCRIPTION
The
.BR getcwd 
function copies the absolute pathname of the current working directory
(GS/OS prefix 0 if not NULL, otherwise GS/OS prefix 8)
into the memory referenced by
.I buf
and returns a pointer to
.IR buf .
The
.I size
argument is the size, in bytes, of the array referenced by
.IR buf .
.LP
If
.I buf
is
.BR NULL ,
space is allocated as necessary to store the pathname.
This space may later be released by
.BR free (3).
.LP
The function
.BR getwd 
is a compatibility routine which calls
.BR getcwd 
with its
.I buf
argument and a size of
.BR MAXPATHLEN
(as defined in the include file
.BR <sys/param.h> ).
Obviously,
.I buf
should be at least
.BR MAXPATHLEN
bytes in length.
.LP
These routines make use of the 
.BR _mapPath (3)
facility.
.SH RETURN VALUES
Upon successful completion, a pointer to the pathname is returned.
Otherwise a
.BR NULL
pointer is returned and the global variable
.IR errno
is set to indicate the error.
In addition,
.BR getwd 
copies the error message associated with
.IR errno
into the memory referenced by
.IR buf .
.SH COMPATIBILITY
These routines are thread safe.
.SH ERRORS
The
.BR getcwd 
function
will fail if:
.RS
.IP \fBEACCESS\fR
Read or search permission was denied for a component of the pathname.
.IP \fBEINVAL\fR
The
.I size
argument is zero, or if pathname mapping is active and the current working
directory has a component which includes the slash ('/') character.  See
.BR _mapPath (3).
.IP \fBENOENT\fR
A component of the pathname no longer exists.
.IP \fBENOMEM\fR
Insufficient memory is available.
.IP \fBERANGE\fR
The
.I size
argument is greater than zero but smaller than the length of the pathname
plus 1.
.RE
.SH BUGS
The
.BR getwd 
function
does not do sufficient error checking and is not able to return very
long, but valid, paths.
It is provided for compatibility and should be avoided when possible.
.SH STANDARDS
The
.BR getcwd 
function
conforms to
.BR "ANSI C" .
The ability to specify a
.BR NULL
pointer and have
.BR getcwd 
allocate memory as necessary is an extension.
.SH HISTORY
The
.BR getwd 
function appeared in 
BSD 4.0.
.SH SEE ALSO
.BR chdir (2),
.BR fchdir (2),
.BR _mapPath (3),
.BR malloc (3),
.BR strerror (3)